Incidence of antitachycardia therapy suspension due to magnet reversion in implantable cardioverter defibrillators

Electromagnetic interference may result in transient or persistent suspension of antitachycardia therapies in ICDs. The incidence of such events has not been assessed so far. Patient charts were retrospectively analyzed for the occurrence of temporary suspension of antitachycardia therapies as it is stored in the Holter of St. Jude Medical or Ventritex ICDs. Follow-up data of 46 patients and 83.7-patient years were analyzed. Overall, 43 episodes of transient ICD inactivation occurred. Twenty-two of these episodes were related to intentional ICD inactivation in the emergency room or during surgery and 12 episodes were related to ICD follow-up. In nine episodes an environmental source of electromagnetic interference is presumed. None of the interactions resulted in persistent ICD inactivation or reprogramming of the devices. The risk for temporary suspension of ICD therapies unrelated to surgery, intentional magnet application in the emergency room, or routine follow-up is 11% per patient and year. Evaluation of its potential sources and the prevalence of ICD inhibition is warranted.     

Echo-enhanced duplex sonography of extracranial vertebral arteries

We sought to investigate the potential benefit in examining extracranial vertebral arteries (ExVA) with an echo contrast agent. A total of 26 patients with insufficiently assessable ExVA underwent extracranial duplex sonography without and with an echo contrast medium. All examinations were recorded and analysed independently by two experienced sonographers. Interrater agreement was fair in assessment of B-mode quality, colour-coding, blooming artefacts, change of vmax, good to very good in all other rated categories. Using an echo contrast medium reduced overall inassessable ExVA by 48% and 36% according to the two raters, respectively. After contrast enhancement, diagnosis was clarified in ExVA formerly inassessable for hypoplasia in 60% vs. 56%, extracranial occlusion in 67% vs. 56% and resistance signal in 63% vs. 45%, respectively. Application of an echo contrast agent leads to clarification of ExVA sonographic diagnosis in approximately one third of poorly examinable patients (35% and 30%, respectively), and contributes in ruling out extracranial occlusion, hypoplasia and resistance signal.     

Sex and the risk of restless legs syndrome in the general population

BACKGROUND: Restless legs syndrome (RLS) is characterized by the desire to move the limbs associated with paresthesias of the legs, a motor restlessness, an intensification of symptoms at rest with relief by activity, and a worsening of symptoms in the evening or at night. Population-based studies are rare, and risk factors in the general population are not known. METHODS: Cross-sectional survey with face-to-face interviews and physical examination among 4310 participants in the Study of Health in Pomerania in northeastern Germany. Participants were aged 20 to 79 years and were randomly selected from population registers. Restless legs syndrome was assessed with standardized, validated questions addressing the 4 minimal criteria for RLS as defined by the International Restless Legs Syndrome Study Group. RESULTS: The overall prevalence of RLS was 10.6%, increasing with age, and women were twice as often affected as men. While nulliparous women had prevalences similar to those among men up to age 64 years, the risk of RLS increased gradually for women with 1 child (odds ratio, 1.98; 95% confidence interval, 1.25-3.13), 2 children (odds ratio, 3.04; 95% confidence interval, 2.11-4.40), and 3 or more children (odds ratio, 3.57; 95% confidence interval, 2.30-5.55). Subjects with RLS had significantly lower quality-of-life scores than those without the syndrome. CONCLUSIONS: Restless legs syndrome is a common disease in the general population, affecting women more often than men. It is associated with reduced quality of life in cross-sectional analysis. Parity is a major factor in explaining the sex difference and may guide further clarification of the etiology of the disease.     

Moyamoya disease complicated by life-threatening epistaxis: first report of a case

OBJECTIVE: Subacute haemorrhage is a common emergency in otorhinolaryngology. Rapid evaluation of the aetiology and localization is a precondition for suitable treatment. We demonstrate a rare case of primarily intractable epistaxis associated with occlusion of the circle of Willis (moyamoya disease). PATIENT: A 38-year-old man presented with a 24-h history of recurrent epistaxis. Anamnesis revealed long-term anticoagulation after heart valve transplantation and arterial hypertension. RESULTS: As a result of several re-bleedings after anterior nasal packing, a re-packing was followed by surgical treatment under general anaesthesia. Four days after discharge the patient presented to the intensive care unit with severe re-bleeding. After removal of a temporary Bellocq packing, interdisciplinary treatment was necessary. Emergency angiography revealed advanced moyamoya disease, with occlusion of both internal carotid arteries. The cerebral blood supply was sustained by an excessive collateral network originating from external carotid anastomoses. This complicated the endovascular treatment, which consisted of embolization of the infraorbital and maxillar arteries with liquid material and coils flanked by Bellocq packing. The patient was doing well at follow-up after 12 months. CONCLUSION: Epistaxis complicating moyamoya disease is rare, and endovascular treatment is difficult due to the high risk of cerebral embolism. Malformations of the cerebral arteries should be considered in the differential diagnosis of intractable epistaxis.     

Effects of handedness and gender on macro- and microstructure of the corpus callosum and its subregions: a combined high-resolution and diffusion-tensor MRI study

The corpus callosum (CC) represents the major commissural tract connecting the two cerebral hemispheres and is supposed to play crucial integrative role in functional hemispheric specialization. The present study examined whether interindividual variations in macro- and microstructure of the human CC are associated with handedness and gender. Therefore, a combined diffusion-tensor (DTI) and high-resolution morphological MRI study was performed on 34 right- and 33 left-handed subjects of both sexes. The mid-sagittal surface areas and quantitative measures of molecular diffusion (relative anisotropy, mean diffusion) of the total CC and its subregions (genu, truncus, posterior third) were determined. Analysis revealed a larger total callosal area in right- as compared to left-handed subjects and in males as compared to females. Throughout all callosal subregions, anisotropy was found to be increased in left-handed as well as in male subjects, while the mean diffusion was diminished only in left-handers. For the posterior third of the CC, a significant negative correlation (r=-0.34) between anisotropy and area was detected in right-handed subjects. Summarized, significant alterations in the molecular diffusion and in the size of the CC with respect to gender and handedness were revealed in the present study. These findings can be interpreted as handedness- and gender-related differences in macro- and microstructure of the callosal pathways. It was demonstrated that the inspection of the callosal microstructure using DTI yields empirical evidence on interhemispheric connectivity that goes well beyond the information revealed by anatomical measurements alone. Thus, DTI has proven to be a useful additional method in cognitive neuroscience.     

Does age influence early recovery from ischemic stroke?

Age is the most important risk factor for developing a stroke. In addition, age may also influence stroke recovery. To allow structured discharge planning, it may be important to consider the influence of age on stroke recovery during the early phase. We studied the effect of patient age on early stroke recovery in a cohort of 2219 unselected stroke patients. Data on functional status (Barthel Index Score) were collected prospectively within 24h after admission, after one week and at discharge for 2219 acute stroke patients treated in 1999 and 2000 at 7 neurological departments in the county of Hesse, Germany. Multiple regression analyses were used to test for an association between age, relative recovery and speed of recovery of ADL after stroke. More than half of the patients (58 %) improved in functional status during hospitalization. 37 % had no change in Barthel Index score and only a small number of patients (5 %) deteriorated during this period. Relative improvement decreased with increasing age: patients younger than 55 years showed an improvement of 67 % of the maximum possible improvement compared whith only 50 % for patients above 55 years (adjusted R² = 0.120, β_age = −0.130, p < 0.001). Age only had a small effect on the speed of recovery. For younger patients functional recovery was slightly faster (adjusted R² = 0.256, β_age = −0.080, p < 0.001). Despite its strong influence on case fatality, age is a poor predictor of functional recovery during the very early phase after stroke. Resulting functional recovery depends much more on the extent of the initial disability. Advanced age should not be regarded as a limiting factor in the early rehabilitation of stroke patients. Received: 3 July 2002, Received in revised form: 16 December 2002, Accepted: 19 December 2002 Correspondence to: Andreas Ferbert, MD     

Human prion diseases: epidemiology and integrated risk assessment

Human prion diseases are devastating and incurable, but are very rare. Fears that the bovine spongiform encephalopathy epizootic would lead to a large epidemic of its presumed human counterpart, variant Creutzfeldt-Jakob disease (vCJD), have not been realised. Yet a feeling of uncertainty prevails in the general public and in the biomedical world. The lack of data on the prevalence of asymptomatic carriers of vCJD compounds this uncertainty. In addition to this problem, Switzerland is currently faced with another issue of major public concern: a recent rise in the incidence of CJD. Here we examine the plausibility of several scenarios that may account for the increase in CJD incidence, including ascertainment bias due to improved reporting of CJD, iatrogenic transmission, and transmission of a prion zoonosis. In addition, we present the design and current status of a Swiss population-wide study of subclinical vCJD prevalence.